Device for uniformly adjusting the moisture content in a compacted mass

ABSTRACT

There is disclosed a device for dewatering a mass of nitrocellulose and replacing the water by alcohol so that the moisture content in the mass is adjusted for a uniformly distributed selected level. The device comprises a press, the cylinder of which is closed at one end by a removable cover mounting on its inner side a perforated plate and into which extends a power driven ram or plunger mounting on its face wall a second perforated plate. The mass of nitrocellulose to be processed is fed into the cylinder space between the two perforated plates. The perforated plate on the cover communicates with a conduit for feeding alcohol into the cylinder and the other perforated plate with a discharge conduit. These two conduits are interconnected by a conduit. A valve is included in the feed conduit upstream of the connection thereof to the discharge conduit and a second valve is included in the interconnecting conduit. First, alcohol is added via the feed conduit by opening the valve in the feed conduit and closing the valve in the interconnecting conduit. Then the valve in the feed conduit is closed and the valve in the interconnecting conduit is opened and, finally, the mass in the cylinder is compacted by activating the plunger. The water is pressed out during the compacting of the mass is discharged through the now open discharge conduit.

United States Patent [191 Kopp [ DEVICE FOR UNIFORMLY ADJUSTING THEMOISTURE CONTENT IN A COMPACTED MASS [75] Inventor: Eugen Kopp,Stuttgart, Germany [73] Assignee: Werner & Pleiderer,

Stuttgart-Feuerbach, Germany [22] Filed: June 1, 1973 [21] Appl. No.:366,070

[30] Foreign Application Priority Data July 19, 1972 Germany 2235255[52] US. Cl 34/70, 34/145, 100/73,

[56] References Cited UNITED STATES PATENTS 3/1938 Wickert, .Ir. 100/1062,221,806 11/1940 Loomis 34/9 2,331,126 10/1943 Loomis 34/70 FOREIGNPATENTS OR APPLICATIONS 1,164,298 2/1964 Germany 34/70 [451 Aug.- 13,1974 Primary E.taminerl(enneth W. Sprague Assistant Examiner.lames C.Yeung Attorney, Agent, or Firm-Plane, Baxley & Spiecens ABSTRACT Thereis disclosed a device for dewatering a mass of nitrocellulose andreplacing the water by alcohol so that the moisture content in the massis adjusted for a uniformly distributed selected level. The devicecomprises a press, the cylinder of which is closed at one end by aremovable cover mounting on its inner side a perforated plate and intowhich extends a power driven ram or plunger mounting on its face wall asecond perforated plate. The mass of nitrocellulose to be processed isfed into the cylinder space between the two perforated plates. Theperforated plate on the cover communicates with a conduit for feedingalcohol into the cylinder and the other perforated plate with adischarge conduit. These two conduits are interconnected by a conduit. Avalve is included in the feed conduit upstream of the connection thereofto the discharge conduit and a second valve is included in theinterconnecting conduit. First, alcohol is added via the feed conduit byopening the valve in the feed conduit and closing the valve in theinterconnecting conduit. Then the valve in the feed conduit is closedand the valve in the interconnecting conduit is opened and, finally, themass in the cylinder is compacted by activating the plunger. The wateris pressed out during the compacting of the mass is discharged throughthe now open discharge conduit.

U lTll DEVICE FOR UNIFORMLY ADJUSTING THE MOISTURE CONTENT IN ACOMPACTED MASS SPECIFICATION The present invention relates to a devicefor dewatering a pliable mass and replacing the removed water by anotherliquid; more particularly, the invention relates to a device fordewatering a pliable mass of nitrocellulose and replacing the removedwater by alcohol.

BACKGROUND There are known presses for the above-referred to purpose inwhich a power driven ram or plunger slidable in the cylinder of thepress mounts on its face wall a perforated plate which communicates witha discharge conduit and the cylinder is closed by a cover at its endopposite to the end through which the plunger is extended into thecylinder. This cover mounts on its inside a perforated plate whichcommunicates with a liquid discharge conduit. Pressure devices of thiskind are operated by feeding alcohol into the mass of nitrocellulose tobe processed and by dewatering the mass by compacting the same, i.e., bya two-stage operation.

There is further known, from German Patent No. 1,164,298, a device inwhich a press has a single cylinder in which a ram'or plunger isslidably driven by the power drive of the press. The cylinder is closedat its end opposite to the end through which the plunger extends intothe cylinder by a pivotal cover which communicates with a feedline forfeeding alcohol into the cylinder. The liquid, such as water, pressedout from the nitrocellulose or other mass during the compacting of thesame is discharged via a perforated plate mounted on the face wall ofthe plunger and communicating with a discharge conduit.

It has been found that dewatering of nitrocellulose in devices asheretofore referred to makes it difficult to distribute the addedalcohol uniformly within the mass, particularly with respect to residualliquid still present in the massafter compacting thereof. As is obvious,compacting of the mass by the ram or plunger of the press is moreeffective adjacent to the plunger than in portions of the mass that aremore remote from the plunger. This is caused by the frictionalresistance experienced by the mass at the inner wall of the cylinder andwhich must be overcome by the force transmitted by the plunger to themass. As a result, there is a variation of the density of the mass froma maximal density at the face of the plunger to a minimal density at thetop of the mass and such decrease is always in the direction in whichthe pressure by the plunger movement is transferred to the mass. Inpractice, there is formed on the plunger a generally cone-shaped cakethe base portion of which has the highest density. As a result, liquidto be removed from the mass will escape from the same only to limitedextent and such escape becomes less and less uniform as the compactingforce increases. A non-uniform distribution of the moisture content ismost undesirable as further processing of nitrocellulose makes itabsolutely necessary that the remaining moisture content in the mass isadjusted to a predetermined uniform level.

THE INVENTION It is a broad object of the invention to provide novel andimproved device for treatment of a mass of nitrocellulose and other massso that the moisture content of the mass can be accurately reduced to apredetermined level and is uniformly distributed throughout the entiremass.

A more specific object of the invention is to provide a novel andimproved device of the general kind abovereferred to which permitsdewatering of the mass and feeding of another liquid such as alcoholinto the same by a one-stage operation.

SUMMARY OF THE INVENTION The above-pointed out objects, features andadvantages of the invention and other objects, features and advantageswhich will be pointed out hereinafter are obtained by providing a presswith an open-ended cylinder into which a power driven plunger or ramextends from one end of the cylinder. The other end of the cylinder isclosed by a removable cover preferably hinged to the cylinder end. Thecover and the facing end of the plunger each mount a perforated or sieveplate. The mass of nitrocellulose to be processed is fed into thecylinder space between these plates.

The plate on the cover' communicates with a feed conduit and the plateon the plunger with a discharge conduit. A third conduit interconnectsthese two conduits. A valve is included in the feed conduit upstream ofthe connection thereof when the third conduit and a second valveis'included in the third conduit.

The press is operated by first opening the valve in the feed conduit andclosing the valve in the interconnecting third conduit for feedingalcohol into the cylinder space. The valve in the feed conduit is thenclosed and the valve in the interconnecting conduit is opened. When nowthe mass in the cylinder is compacted by power driving the plunger, thewater then expelled from the mass is discharged from the cylinderthrough the third conduit.

DETAILED DESCRIPTION OF THE INVENTION In the single figure of thedrawing a diagrammatic sectional view of a press according to theinvention is shown by way of illustration and not by way of limitation.

Referring now to the figure in detail, only those components of thepress which are essential for the understanding of the invention areillustrated. It should be understood that the press is conventionalexcept with respect to components which are illustrated and described.

There is shown a cylinder 1 of a press open at both ends. The upper endof the cylinder is closable by a cover plate 2 which can be mounted inany convenient manner, i.e., it may be hinged to the cylinder. A ram orplunger 3 is slidable in the cylinder and is power driven by a piston 4.The press cake, such as a mass of nitrocellulose 7, to be processed inthe cylinder space 1' limited by cover 2 and the upper face of plunger3. As it is indicated, the mass is compacted by pressure applied to itin response to an upward movement of piston 4 and thus of plunger 3 asis indicated by an arrow P. As a result of such compacting of the mass apressure cone 7 is formed which is tapered in the direction of theapplied pressure. As previously explained, the density in this massforming the cone is highest at its base and decreases gradually towardthe apex of the cone.

Cover 2 mounts on its side facing plunger 3 a perforated plate 5.Similarly, the side of the plunger facing cover 2 mounts a perforatedplate 6. Perforated plate 5 communicates with a duct 8 in cover 2 andperforatedplate 6 communicates with a duct 9 extending through plunger3. Both ducts are interconnected via pipes 8 and 9' respectively to aconduit 10 for collecting liquid released from the mass when the same issubjected to the aforedescribed pressure and for discharging suchcollected liquid through conduit 10 as it is indicated by an arrow.Moreover, duct 8 in cover 2 is connected via pipe 8 with a feed pipe 11for feeding liquid so that when a control valve 12 included in pipe 11upstream of the connection with conduit 10 is opened and a correspondingcontrol valve 13 in conduit 10 is closed liquid can be fed into thecylinder space 1' containing mass 7 before the mass is compacted, suchliquid being usually alcohol.

Conversely, during the compacting operation, valve 12 is closed andvalve 13 is opened to permit discharge of squeezed-out liquid, usuallywater, via perforated plate 5 and duct 8 in cover plate 2. As a resultof such arrangement, the released water can be discharged via the upperperforated plate 5 and the duct 8 communicating therewith, therebyconsiderably increasing the overall performance of the press.

While the invention has been described in detail with respect to acertain new preferred example and embodiment of the invention, it willbe understood by those skilled in the art, after understanding theinvention, that various changes and modifications may be made withoutdeparting from the spirit and scope of the invention, and it isintended, therefore, to cover all such changes and modifications ,in theappended claims.

What is claimed:

1. A device for controlled displacement of water contained in a pliablemass of nitrocellulose by alcohol, said device comprising:

an upright cylinder closed at the top end by a closure member and openat the other end;

a pressure plunger slidably extending into the cylinder from the openend thereof for defining within the cylinder a receiving space ofvariable volume between the plunger and the closure member for receivinga pliable mass of nitrocellulose, the pres sure stroke of the plungerbeing toward the top end of the cylinder;

a first perforated plate mounted on the side of the closure memberfacing the plunger;

a second perforated plate mounted on the plunger on the side facing theclosure member;

a first conduit communicating with said first perforated plate on theside thereof facing the closure member for feeding alcohol into saidspace and discharging water therefrom;

a second conduit communicating with the second perforated plate on theside thereof facing the plunger for discharging water contained in saidspace;

a third conduit interconnecting the first and the second conduit forsimultaneously discharging liquid pressed out of the mass through bothsaid perforated plates;

a feed conduit communicating with said first conduit for feeding alcoholinto said space through said first perforated plate;

a first control valve included in said feed conduit for controlling thefeed of alcohol into said space; and

a second control valve included in said interconnecting conduit forselectively closing the flow of pressed out water through saidinterconnecting conduit,

opening of the first valve and closing of the second valve establishinga connection for feeding alcohol into said space through the firstperforated plate and closing of the first valve and opening of thesecond valve connecting both perforated plates to the interconnectingthird conduit, displacement of the plunger toward said closure membercorrespondingly reducing said receiving space causing water and alcoholto be pressed out of the mass, said pressedout water and alcohol beingdischarged at both ends of mass through said perforated plates.

2. The device according to claim 1 wherein said closure member is acover plate removably attached to the respective end of the cylinder,said first conduit communicating with the first perforated plate throughsaid cover plate.

3. The device according to claim 1 wherein said second conduitcommunicates with said second perforated plate through the body of saidplunger.

1. A device for controlled displacement of water contained in a pliablemass of nitrocellulose by alcohol, said device comprising: an uprightcylinder closed at the top end by a closure member and open at the otherend; a pressure plunger slidably extending into the cylinder from theopen end thereof for defining within the cylinder a receiving space ofvariable volume between the plunger and the closure member for receivinga pliable mass of nitrocellulose, the pressure stroke of the plungerbeing toward the top end of the cylinder; a first perforated platemounted on the side of the closure member facing the plunger; a secondperforated plate mounted on the plunger on the side facing the closuremember; a first conduit communicating with said first perforated plateon the side thereof facing the closure member for feeding alcohol intosaid space and discharging water therefrom; a second conduitcommunicating with the second perforated plate on the side thereoffacing the plunger for discharging water contained in said space; athird conduit interconnecting the first and the second conduit forsimultaneously discharging liquid pressed out of the mass through bothsaid perforated plates; a feed conduit communicating with said firstconduit for feeding alcohol into said space through said firstperforated plate; a first control valve included in said feed conduitfor controlling the feed of alcohol into said space; and a secondcontrol valve included in said interconnecting conduit for selectivelyclosing the flow of pressed out water through said interconnectingconduit, opening of the first valve and closing of the second valveestablishing a connection for feeding alcohol into said space throughthe first perforated plate and closing of the first valve and opening ofthe second valve connectiNg both perforated plates to theinterconnecting third conduit, displacement of the plunger toward saidclosure member correspondingly reducing said receiving space causingwater and alcohol to be pressed out of the mass, said pressedout waterand alcohol being discharged at both ends of mass through saidperforated plates.
 2. The device according to claim 1 wherein saidclosure member is a cover plate removably attached to the respective endof the cylinder, said first conduit communicating with the firstperforated plate through said cover plate.
 3. The device according toclaim 1 wherein said second conduit communicates with said secondperforated plate through the body of said plunger.